I have no idea what you are talking about, but it seems you do not understand how shape layers work. These operations do not modify the input paths, they modify the rendered results. You actual paths will always be visible. There is nothing wrong.

I tried to get this to work exactly how you want it with merge paths and I see this specific scenario is not possible. I am not sure exactly why you need it to work in this specific setup. why not just make 2 diamonds as two separate paths? but if there is a reason, remember you can combine shapes and masks in the same layer (both vector) and force a shape to behave

sorry about that , what I want looks like this: ◇ ◇ but it works like two 5-vecter-points shape

You will need to reveal the properties of your layer then. As Roei illustrated, this works just as intendend when set up properly, so you are doing something with your shape layer that you are not telling us. Perhaps your grouping is awry, perhaps you have transformed it in some way. Impossible to tell.